Time-Controlled-PRV Cable-Head Cutter For Line Conveyed Tools

ABSTRACT

A cable head line cutter tool comprising an internal mandrel anchored to a line and releasably held in an initial position by a pressure relief valve which may act in coordination with a locking mechanism disposed within an outer housing of the cable head cutter tool. When a tensile load is applied to the line sufficient to overcome an opening pressure of the pressure relief valve and a mechanical resistance acting upon the locking mechanism, and maintained for a duration sufficient to overcome a hydraulic resistance acting upon the locking mechanism, the internal mandrel may become released to travel within the outer housing. If the tensile load applied to the line is sufficient to open the pressure relief valve, release the mandrel from the locking mechanism, and maintained for sufficient duration, the mandrel may cause a line cutter device of the cable head line cutter tool to cut the line.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION Field of the Invention

This invention relates generally to mechanical devices used in wells such as oil and gas wells. More particularly, apparatuses and methods are provided for cutting a line used to deploy a tool in a well if the tool becomes stuck in the well. A line may be a slickline, braided line, electromechanical line, flexible rod, or coiled tubing.

Background of the Invention

In this application, the terms “wireline” and “wireline cable” may generically refer an electromechanical line having one or more conductors.

A variety of mechanical devices or tools are used in wells, for such purposes as logging the properties of the formation surrounding the well, taking samples of the formation, perforating the formation and/or wellbore casing, well intervention, and other purposes. During such operations, commonly performed using a wireline, an accumulation of material within the hole, high differential pressure between the wellbore and the rock formations, or the occurrence of mechanical or hydraulic malfunctions, may present operational complications making it impossible to retrieve a tool from a well using the wireline supporting the tool. Other factors which may contribute to tools becoming stuck may include the length and profile of the wellbore, for example wherein doglegs may contribute to the tool experiencing increased drag, or the weight of the tools themselves. Under these circumstances it may be desirable to release the line from the tool that is lodged in the well, allowing the tool to be retrieved using more suitable equipment.

Different mechanisms suitable for releasing a line from a stuck tool are known in the art. For example, U.S. Pat. No. 5,109,921 discloses a releasable tool with first and second shear pin arrangements. U.S. Pat. No. 5,568,836 discloses a release device having a latch mechanism and a time delay mechanism that is actuated after a time interval has elapsed. However, existing technologies and techniques are typically limited in their ability to flexibly adapt to conditions which may be encountered in the field.

In many wireline retrieval operations, particularly tight hole operations, it may often be desirable to apply a tensile load on the wireline in an attempt to free the stuck tool without cutting the wireline. For example, an operator may find it desirable to slowly increase tension on the wireline, and then hold the tension for an extended period of time to try to dislodge the tools without triggering the cutting device. In another example, the operator may desire to apply an overload tension in excess of the triggering load of the cutting device to try to dislodge the tool without triggering the cutting device. With most conventional cutting devices, application of a tensile load over a long period of time and application of an overload tension may cause the cutting device to be inadvertently triggered.

Consequently, there remains a need in the art for wireline cutting devices which allow the triggering load to be exceeded for a finite period of time without causing the wireline to be cut, and this need in the art extends equally to other forms of lines which may be used to convey a tool in a well. Such cutting devices would be particularly well received if they provided the operator the option of reducing the line tension shortly after the over-pull to avoid cutting the wireline, or maintaining the over-pull to trigger the wireline to be cut.

BRIEF SUMMARY OF SOME OF THE PREFERRED EMBODIMENTS

While the embodiments that follow are directed to applications comprising an electromechanical line having one or more conductors, it should be understood that each embodiment may alternatively comprise other forms of lines allowing conveyance of wellbore tools, including, but not limited to, slicklines, braided lines, electromechanical lines, flexible rod, coiled tubing, or similar means of conveyance.

These and other needs in the art are addressed in a first embodiment by a time-controlled cable-head cutter tool adapted for use in wellbore applications with line conveyed tools comprising a pressure relief valve. The first embodiment may comprise an outer housing, a mandrel adapted for longitudinal movement within the housing, a pressure piston comprising a pressure relief valve, a restrictor orifice, and one or more check valves, a biasing mechanism acting against the pressure piston, a balancing piston, a mechanical or non-mechanical cutting mechanism disposed at a first end of the cable-head cutter tool, and a connection housing disposed at a second end of the cable-head cutter tool wherein a wireline cable may be terminated.

These and other needs in the art are addressed in a second embodiment by a time-controlled cable-head cutter tool adapted for use in wellbore applications with line conveyed tools comprising a tripping valve mechanism and a pressure relief valve. The second embodiment may comprise an outer housing, a mandrel adapted for longitudinal movement within the housing, a pressure piston comprising a pressure relief valve, a restrictor orifice, and one or more check valves, a biasing mechanism acting against the pressure piston, a tripping valve mechanism, a balancing piston, a mechanical or non-mechanical cutting mechanism disposed at a first end of the cable-head cutter tool, and a connection housing disposed at a second end of the cable-head cutter tool wherein a wireline cable may be terminated.

These and other needs in the art are addressed in a third embodiment by a time-controlled cable-head cutter tool adapted for use in wellbore applications with line conveyed tools comprising a single-trigger mechanism and a pressure relief valve. The third embodiment may comprise an outer housing, a mandrel adapted for longitudinal movement within the housing, a pressure piston comprising a pressure relief valve, a restrictor orifice, and one or more check valves, a biasing mechanism acting against the pressure piston, an adjustable triggering mechanism, a balancing piston, a mechanical or non-mechanical cutting mechanism disposed at a first end of the cable-head cutter tool, and a connection housing disposed at a second end of the cable-head cutter tool wherein a wireline cable may be terminated.

Each of the three embodiments may allow a wireline cable passing longitudinally along a central axis of the cable-head cutter tool to be cut based upon a predetermined load being applied to the cable-head cutter tool, after a predetermined time delay has been passed, or combinations thereof. Alternatively, each of the three embodiments may allow the cable-head cutter tool to be reset to an initial configuration without having cut the wireline cable by reducing or relaxing the load applied to the cable-head cutter tool. To increase the weight of the tool string one or more hollow tools, commonly referred as over-the-line sinker bars, may be inserted between the outer housing and the fishing neck of the cable-head cutter tool. Externally mounted or clamp-on subs or tools, such as sinker bars or dummy heads, may be mounted over the deployment line section right above the cable head cutter tool fishing neck. These devices may be removed from the well along with the line once the cable head cutter has been activated and the line is cut. An example of such sub may be a dummy head required to support the functionality of a tool catcher sub, which may be part of surface pressure control system used in live wells.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent embodiments do not depart from the spirit and scope of the invention as set forth in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:

FIGS. 1 a-c illustrate an embodiment of a time-controlled cable-head cutter apparatus comprising a pressure relief valve in a closed configuration;

FIGS. 2 a-c illustrate an embodiment of a time-controlled cable-head cutter apparatus comprising pressure relief valve after a wireline cable has been cut;

FIGS. 3 a-c illustrate an embodiment of a time-controlled cable-head cutter apparatus comprising a tripping valve locking mechanism and a pressure relief valve in a closed configuration;

FIGS. 4 a-c illustrate an embodiment of a time-controlled cable-head cutter apparatus comprising a tripping valve locking mechanism and a pressure relief valve in a released configuration;

FIGS. 5 a-c illustrate an embodiment of a time-controlled cable-head cutter apparatus comprising tripping valve locking mechanism and a pressure relief valve after a wireline cable has been cut;

FIGS. 6 a-c illustrate an embodiment of a time-controlled cable-head cutter apparatus comprising a single trigger-sleeve locking mechanism and a pressure relief valve in a closed configuration;

FIGS. 7 a-c illustrate an embodiment of a time-controlled cable-head cutter apparatus comprising a single trigger-sleeve locking mechanism and a pressure relief valve in a released configuration; and

FIGS. 8 a-c illustrate an embodiment of a time-controlled cable-head cutter apparatus comprising a single trigger-sleeve locking mechanism and a pressure relief valve after a wireline cable has been cut.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following description the term proximal is used to describe the portion of the part being referred to that is closest to the well opening, or well mouth, and the term distal is used to refer to the portion of the part being referred to that is furthest from the well opening. Although the embodiments that follow illustrate applications comprising a wireline having one or more conductors, it should be understood that each embodiment may alternatively comprise other forms of lines allowing conveyance of wellbore tools, including, but not limited to, slicklines, braided lines, electromechanical lines, flexible rod, coiled tubing, or similar means of conveyance.

FIGS. 1 a through 1 c and 2 a through 2 c illustrate an embodiment of time-controlled cable-head cutter tool 100 adapted for use in wellbore applications with wireline conveyed tools, comprising a pressure relief valve. FIGS. 1 a through 1 c illustrate cable-head cutter tool 100 in a closed configuration, and FIGS. 2 a through 2 c illustrate cable-head cutter tool 100 after wireline cable 401 has been cut.

FIGS. 3 a through 3 c, 4 a through 4 c, and 5 a through 5 c illustrate an embodiment of time-controlled cable-head cutter tool 200 adapted for use in wellbore applications with wireline conveyed tools, comprising a tripping valve locking mechanism and a pressure relief valve. FIGS. 3 a through 3 c illustrate cable-head cutter tool 200 in a closed configuration, FIGS. 4 a through 4 c illustrate cable-head cutter tool 200 in a released configuration, and FIGS. 5 a through 5 c illustrate cable-head cutter tool 200 after wireline cable 401 has been cut.

FIGS. 6 a through 7 c, 7 a through 7 c, and 8 a through 8 c illustrate an embodiment of time-controlled cable-head cutter tool 300 adapted for use in wellbore applications with wireline conveyed tools, comprising a single trigger-sleeve locking mechanism and a pressure relief valve. FIGS. 6 a through 6 c illustrate cable-head cutter tool 300 in a closed configuration, FIGS. 7 a through 7 c illustrate cable-head cutter tool 300 in a released configuration, and FIGS. 8 a through 8 c illustrate cable-head cutter tool 300 after wireline cable 401 has been cut.

In embodiments, wireline cable 401 may be any known wireline cable suitable for use in wellbore applications with wireline conveyed tools, including electromechanical cable, braided cable, slick line cable, or similar wireline cable, and may comprise a specified maximum suggested working tension. Examples of such wireline cables may include, but not be limited to Camesa® wireline cables such as 1N29-EHS, 1N32-EEHS, 1Q36-EHS ECOSEAL, 7H47-EHS, 7H49-EEHS, and Schlumberger® wireline cables such as StreamLINE and TuffLINE. Wireline cable 401 may be configured to enter a proximal end, extend through an axially centered channel, and terminate at a distal end of cable-head cutter tool 100,200,300.

Time-controlled cable-head cutter tool 100,200,300 may be comprised of an outer housing or casing, a mandrel, and a plurality of additional parts, components, or elements configured to function together which may allow wireline cable 401, passing longitudinally along a central axis from a proximal end of cable-head cutter tool 100,200,300 to a terminating connection 420 at a distal end of cable-head cutter tool 100,200,300, to be cut by cutting mechanism 410 based upon a predetermined load being applied to cable-head cutter tool 100,200,300, after a predetermined time delay has been passed, or combinations thereof. Alternatively, the configuration of cable-head cutter tool 100,200,300 may allow cable-head cutter tool 100,200,300 to be reset to an initial configuration without having cut wireline cable 401.

The outer housing system may be generally tubular in shape, and may be comprised of several sections, components, or parts which may be connected to each other, including fishing neck 101,201,301, cutter housing 102,202,302, seal housing 103,203,303, drive housing 111,211,311, filling sub 112,212,312, release housing 318 (in the third embodiment), adjustment housing 323 (in the third embodiment), balance housing 126,226,326, floater sub 128,228,328, and connection housing 132,232,332, each having similar outer diameters. The mandrel may extend longitudinally within the casing and may be comprised of several sections, components, or parts which may be connected to each other, including cutter press 140,240,340, drive mandrel 142,242,342, release mandrel 344 (in the third embodiment), connector mandrel 346 (in the third embodiment), and balance mandrel 148,248,348. A first annular fluid chamber between the housing and mandrel may be formed beginning at the distal portion of seal housing 103,203,303 and through the central portion of cable-head cutter tool 100,200,300 to a proximal portion of balance housing 126,226,326 located proximally relative to balancing piston 150,250,350.

Fishing neck 101,201,301 may be formed in any known manner, using a known design which may allow cable-head cutter tool 100,200,300 to be fished from a wellbore after wireline cable 401 has been cut. Fishing neck 101,201,301 may further be formed having a reduced diameter distal portion adapted for threaded connection to a proximal portion of cutter housing 102,202,302, and may provide an axially centered channel through which wireline cable 401 may be run.

Cutter housing 102,202,302 may be formed having an internally threaded proximal portion adapted for threaded connection to the reduced diameter distal portion of fishing neck 101,201,301, and an internally threaded distal portion adapted for threaded connection to a reduced diameter proximal portion of seal housing 103,203,303. Cutter housing 102,202,302 may be configured having an internal profile adapted for housing any known cable cutting mechanism 410, and may provide an axially centered channel through which wireline cable 401 may be run. The internal profile of cutter housing 102,202,302 may further comprise cutting mechanism seat 415 located distally to cable cutting mechanism 410 which may comprise a profiled surface about its distal portion.

Wireline cable cutting mechanism 410 may comprise any known cable cutting mechanism capable of cutting wireline cable 401 that is compression-activated or adapted to be activated based upon a predetermined force being applied to cutting mechanism 410. Examples of such cable cutting mechanisms may include, but not be limited to any suitable mechanism which may cut, part, or sever a line (generically herein, “cut”), including mechanical cutting mechanisms comprising wedge-knife or double-knife compression cutters, or non-mechanical cutting mechanisms comprising ballistic cutters or chemical cutters. While the embodiments that follow illustrate cutting mechanism 410 as being coupled to the outer housing system, it should be understood that in alternative embodiments not illustrated, line cutting mechanism 410 may be coupled to the internal mandrel system and may be caused to cut line 401 as a result of contacting one or more internal surfaces or profiles of the outer housing system.

In embodiments, wireline cable cutting mechanism may be of a form comprising cable cutter 412 disposed between opposing wedges 411,413. Cable cutter 412 may be biased by cutter body 414 toward a first position wherein a cutting surface of cable cutter 412 is not in contact with wireline cable 401. Upon having sufficient force applied to the distal surface of cutting mechanism 410 by cutter press 140,240,340, cable cutter 412 may be directed toward a second position as shown in FIGS. 2 a, 5 a, and 8 a by axial movement of wedge 413 toward a proximal direction, thus cutting wireline cable 401.

Cutter press 140,240,340 may be formed having a generally flat proximal surface perpendicular to the longitudinal axis of cable-head cutter tool 100,200,300 and having an opening at its distal portion adapted for threaded connection to a proximal end of drive mandrel 142,242,342. A proximal portion of cutter press 140,240,340 may have an outer diameter smaller than the internal diameter of cutter housing 102,202,302, thus forming an annular gap between the proximal portion of cutter press 140,240,340 and cutter housing 102,202,302, and may be provided with an axially-centered aperture through which wireline cable 401 may be run. An outer diameter of the distal portion of cutter press 140,240,340 may be in slidable contact with the inner surface of cutter housing 102,202,302 and may further be formed having a proximal surface adapted for resting contact against the distal portion of cutting mechanism seat 415. One or more sealing elements 141,241,341 may be disposed within one or more inner recessed surfaces of the distal portion of cutter press 140,240,340, which may be positioned distally to the threaded connection between cutter press 140,240,340 and drive mandrel 142,242,342 when fully engaged. In the first and third embodiments, sealing element 141,341 may seal against drive mandrel 142,342, while in the second embodiment, sealing element 241 may seal against first sleeve member 281.

Seal housing 103,203,303 may be formed having a reduced diameter proximal portion adapted for threaded connection to a distal portion of cutter housing 102,202,302 and a reduced diameter distal portion adapted for threaded connection to a proximal portion of drive housing 111,211,311. Seal housing 103,203,303 may be provided with an internal bore sized to allow a proximal portion of seal housing 103,203,303 to remain in slidable contact with an outer surface of drive mandrel 142,342 (in the first and third embodiments) or first sleeve member 281 (in the second embodiment), and provide an annular fluid cavity about a distal portion of seal housing 103,203,303 located between seal housing 103,203,303 and drive mandrel 142,342 (in the first and third embodiments) or first sleeve member 281 (in the second embodiment). One or more loaded lip seals 104,204,304 and one or more sealing elements 105,205,305 may be disposed within one or more inner recessed surfaces of the proximal portion of seal housing 103,203,303 and in slidable contact with a proximal portion of drive mandrel 142,342 (in the first and third embodiments) or first sleeve member 281 (in the second embodiment). One or more sealing elements 106,206,306 may be disposed in one or more recessed outer surfaces of the proximal portion of seal housing 103,203,303, which may be positioned proximally to the threaded connection between seal housing 103,203,303 and cutter housing 102,202,302. Similarly, one or more sealing elements 110,210,310 may be disposed in one or more recessed outer surfaces of the distal portion of seal housing 103,203,303, which may be positioned distally (in the first and second embodiments) or proximally (in the third embodiment) to the threaded connection between seal housing 103,203,303 and drive housing 111,211,311. Seal housing 103,203,303 may be provided with one or more jam screws 107,207,307 and sealing discs 108,208,308 to allow for a fluid to be introduced into the first annular fluid chamber of cable-head cutter tool 100,200,300. Seal housing 103,203,303 may also be provided with one or more counter bores 109,209,309 for use with a spanner wrench. In the second embodiment, a distal portion of seal housing 203 may be provided with an expanded internal bore having a size and profile adapted to receive a distal profile of first sleeve member 281.

Drive housing 111,211,311 may be formed having an internally threaded proximal portion adapted for threaded connection to the reduced diameter distal portion of seal housing 103,203,303, and an internally threaded distal portion adapted for threaded connection to a reduced diameter proximal portion of filling sub 112,212,312. In the first and second embodiments, a distal portion of drive housing 111,211 may be formed having an internal bore which may provide shoulder 111 a,211a, and may be formed having an inner cross-sectional profile comprising one or more flat surfaces. For example, a distal portion of drive housing 111,211 may be formed having a hexagonal inner cross-sectional profile.

Drive mandrel 142,242,342 may be formed having a proximal portion adapted for threaded connection to cutter press 140,240,340, an enlarged distal portion adapted to threadably receive a proximal portion of balance mandrel 148,248 (in the first and second embodiments) or release mandrel 344 (in the third embodiment), and an axially centered channel through which wireline cable 401 may be run. In the first and third embodiments, drive mandrel 142,342 may be formed having a diameter about a central portion of its length which may allow drive mandrel 142,342 to remain in slidable contact with a proximal inner diameter of seal housing 103,303. In the second embodiment, drive mandrel 242 may be formed having a diameter about a central portion of its length which may allow first sleeve member 281, surrounding drive mandrel 242, to remain in slidable contact with a proximal inner surface of seal housing 203. One or more sealing elements 143,243,343 may be disposed within one or more inner recessed surfaces of the distal portion of drive mandrel 142,242,342, which may be positioned proximally to the threaded connection between drive mandrel 142,242,342 and balance mandrel 148,248 (in the first and second embodiments) or release mandrel 344 (in the third embodiment). The enlarged distal portion of drive mandrel 142,242,342 may be formed having an outer cross-sectional profile comprising one or more flat surfaces which may remain in slidable contact with the one or more flat inner surfaces of drive housing 111,211,311. For example, the enlarged distal portion of drive mandrel 142,242,342 may be formed having a hexagonal outer cross-sectional profile. Each of the one or more flat surfaces of the distal portion of drive mandrel 142,242,342 may further comprise one or more recessed longitudinal channels allowing fluid communication between a proximal surface of the distal portion of drive mandrel 142,242,342 to a distal surface of the distal portion of drive mandrel 142,242,342 and vice-versa.

Filling sub 112,212,312 may be formed having a reduced diameter proximal portion adapted for threaded connection to a distal portion of drive housing 111,211,311 and a reduced diameter distal portion adapted for threaded connection to a proximal portion of balance housing 126,226 (in the first and second embodiments) or release housing 318 (in the third embodiment). One or more sealing elements 113,213,313 may be disposed in one or more recessed outer surfaces of the proximal portion of filling sub 112,212,312, which may be positioned distally to the threaded connection between filling sub 112,212,312 and drive housing 111,211,311. Similarly, one or more sealing elements 116,216,316 may be disposed in one or more recessed outer surfaces of the distal portion of filling sub 112,212,312 which may be positioned distally to the threaded connection between filling sub 112,212,312 and balance housing 126,226 (in the first and second embodiments) or release housing 318 (in the third embodiment). Filling sub 112,212,312 may be provided with one or more jam screws 114,214,314 and sealing discs 115,215,315 to allow for a fluid to be introduced into the first annular fluid chamber of cable-head cutter tool 100,200,300. Filling sub 112,212,312 may also be provided with one or more counter bores 117,217,317 for use with a spanner wrench.

Continuing to traverse longitudinally from a proximal end toward a distal end in the third embodiment, cable-head cutter tool 300 may comprise embodiment-specific housing and mandrel members, including release housing 318, release mandrel 344, adjustment housing 323, and connector mandrel 346.

Release housing 318 may be formed having an internally threaded proximal portion adapted for threaded connection to the reduced diameter distal portion of filling sub 312, and an internally threaded distal portion adapted for threaded connection to a proximal portion of adjustment mandrel 319. Release housing 318 may be formed having internal shoulders 318 a (proximal) and 318 b (distal) about a middle portion of release housing 318.

Release mandrel 344 may be formed having a proximal portion adapted for threaded connection to the enlarged diameter distal portion of drive mandrel 342, a reduced diameter distal portion adapted for threaded connection to an enlarged proximal portion of connector mandrel 346, and an axially centered channel through which wireline cable 401 may be run. Additional details of release mandrel 344 will be presented in detail for cable-head cutter tool 300 separately below.

Adjustment housing 323 may be formed having an internally threaded proximal portion adapted for threaded connection to a reduced-diameter distal portion of adjustment mandrel 319 wherein adjustment mandrel 319 may further comprise a reduced-diameter proximal portion adapted for threaded connection to an internally threaded distal portion of release housing 318. A proximal surface of adjustment mandrel 319 may be formed having a shoulder, seat, or recess adapted to receive a distal portion of biasing element 387 and may further comprise a recessed radial profile adapted to receive a distal lip of split ring retainer 386. Adjustment housing 323 may further be formed having a reduced diameter distal portion adapted for threaded connection to a proximal portion of balance housing 326. One or more sealing elements 320 may be disposed in one or more recessed outer surfaces of the proximal portion of adjustment mandrel 319, which may be positioned proximally to the threaded connection between adjustment mandrel 319 and release housing 318. Similarly, one or more sealing elements 324 may be disposed in one or more recessed outer surfaces of the distal portion of adjustment mandrel 319, which may be positioned distally to the threaded connection between adjustment mandrel 319 and adjustment housing 323. Additionally, one or more sealing elements 325 may be disposed in one or more recessed outer surfaces of the distal portion of adjustment housing 323, which may be positioned distally to the threaded connection between adjustment housing 323 and balance housing 326. Adjustment ring 321 may surround adjustment mandrel 319 and may be provided with one or more adjustment keys 322 which allow rotating the adjustment mandrel to vary the position of trigger sleeve 385 in relation to release mechanism, dog clutch, load release latch, or collet 382. Adjustment housing 323 may be provided with one or more counter bores 323 a for use with a spanner wrench.

Connector mandrel 346 may be formed having an enlarged diameter proximal portion adapted to threadably receive a distal portion of release mandrel 344, an enlarged diameter distal portion adapted to threadably receive a proximal portion of balance mandrel 348, and an axially centered channel through which wireline cable 401 may be run. One or more sealing elements 345 may be disposed within one or more inner recessed surfaces of the proximal portion of connector mandrel 346, which may be positioned distally to the threaded connection between release mandrel 344 and connector mandrel 346. Similarly, one or more sealing elements 347 may be disposed within one or more inner recessed surfaces of the distal portion of connector mandrel 346, which may be positioned proximally to the threaded connection between connector mandrel 346 and balance mandrel 348.

Balance housing 126,226,326 may be formed having an internally threaded proximal portion adapted for threaded connection to the reduced diameter distal portion of filling sub 112,212 (in the first and second embodiments) or adjustment housing 323 (in the third embodiment), and an internally threaded distal portion adapted for threaded connection to a reduced diameter proximal portion of floater sub 128,228,328. Balance housing 126,226,326 may be provided with one or more mud ports 127,227,327 positioned generally distally with respect to balance housing 126,226,326 and proximally to a proximal surface of floater sub 128,228,328. Each of the one or more mud ports 127,227,327 may allow a wellbore fluid to communicate with a second annular fluid chamber formed by an annular cavity between balance housing 126,226,326 and balance mandrel 148,248,348, located distally relative to balancing piston 150,250,350.

Balance mandrel 148,248,348 may be formed having a reduced diameter proximal portion adapted for threaded connection to the distal portion of drive mandrel 142,242 (in the first and second embodiments) or connector mandrel 346 (in the third embodiment), an axially centered channel through which wireline cable 401 may be run, and a distal portion adapted to a desired terminating connection 420.

Balancing piston 150,250,350 may be formed having an inner diameter allowing balancing piston 150,250,350 to remain in slidable contact with balance mandrel 148,248,348, and an outer diameter allowing balancing piston 150,250,350 to remain in slidable contact with balance housing 126,226,326. One or more loaded lip seals 151,251,351 and one or more sealing elements 152,252,352 may be disposed in one or more recessed outer surfaces of balancing piston 150,250,350. Similarly, one or more loaded lip seals 153,253,353 and one or more sealing elements 154,254,354 may be disposed in one or more recessed inner surfaces of balancing piston 150,250,350. Balancing piston 150,250,350 acts to balance pressure differentials between the first and second annular fluid chambers which may result from variances in temperature and/or hydrostatic pressure at different well depths. The details and operation of the balancing piston are described in U.S. Pat. No. 7,290,604, the entire content of which is incorporated herein by reference thereto.

Floater sub 128,228,328 may be formed having a reduced diameter proximal portion adapted for threaded connection to a distal portion of balance housing 126,226,326, and a reduced diameter distal portion adapted for threaded connection to a proximal portion of connection housing 132,232,332. One or more sealing elements 129,229,329 may be disposed in one or more recessed outer surfaces of the proximal portion of floater sub 128,228,328, which may be positioned proximally to the threaded connection between floater sub 128,228,328 and balance housing 126,226,326. Similarly, one or more sealing elements 131,231,331 may be disposed in one or more recessed outer surfaces of the distal portion of floater sub 128,228,328 which may be positioned distally to the threaded connection between floater sub 128,228,328 and connection housing 132,232,332.

Connection housing 132,232,332 may be formed having an internally threaded proximal portion adapted for threaded connection to the reduced diameter distal portion of floater sub 128,228,328 and an internally-threaded distal portion adapted for threaded connection to a reduced diameter proximal portion of lower connection housing 441.

Wireline cable termination 420 may comprise any known wireline cable termination. Examples of such cable termination may include, but not be limited to cones-and-basket, rope socket, or turned-back cable termination methods. In embodiments, wireline cable termination 420 may comprise a rope socket -type termination, wherein wireline cable termination 420 may comprise rope socket body 421, outer cone 422, inner cone 423, and locking nut 424.

Wireline cable terminating connection 430 may comprise any known cable conductor termination connection. Examples of such cable conductor termination connections may include, but not be limited to socket and booth connections or tear drop connections. In embodiments, wireline cable terminating connection 430 may comprise slack wireline conductor 431, crimped and/or soldered connection 432, and electrical contact 433, with soldered connection 432 and electrical contact 433 surrounded by rubber boot 434.

Wireline cable lower connection 440 may comprise any known wireline cable lower connection. Examples of such cable lower connections may include, but not be limited to feedthrough pressure terminal and plunger contact, feedthrough pressure terminal and pin or socket contact, feedthrough isolated rod and plunger contact, or feedthrough isolated rod and pin or socket contact. In embodiments, wireline cable lower connection 440 may comprise lower connection housing 441, electrical feedthrough 443, one or more insulators 444, contact nut 445, coil spring 446, retaining ring 447 (not shown), and contact plunger 448. Lower connection housing 441 may be formed having a reduced diameter proximal portion adapted for threaded connection to a distal portion of connection housing 132,232,332. One or more sealing elements 442 may be disposed in one or more recessed outer surfaces of the proximal portion of lower connection housing 441, which may be positioned proximally to the threaded connection between lower connection housing 441 and connection housing 132,232,332. Lower connection housing 441 may be formed to allow additional equipment to be connected to a distal portion of lower connection housing 441 which together with cable-head cutter tool 100,200,300 may comprise a tool string attached to wireline cable 401.

In embodiments, each of the one or more sealing elements 105,205,305, 106,206,306, 110,210,310, 113,213,313, 116,216,316, 320, 324, 325, 129,229,329, 131,231,331, 141,241,341, 143,243,343,345,347, 152,252,352, 154,254,354, and 442 may be any suitable sealing element, for example an O-ring, and may be formed from any suitable material, for example nitrile (buna-N), ethylene propylene rubber (EPR), fluorocarbon (viton), neoprene, or polyurethane.

EMBODIMENT-SPECIFIC ASPECTS

Each embodiment of cable-head cutter tool 100,200,300 may be provided with a pressure piston assembly 170,270,370 which may act in coordination with additional embodiment-specific componentry. Pressure piston assembly 170,270,370 may allow fluid communication from a proximal surface of pressure piston assembly 170,270,370 to a distal surface of pressure piston assembly 170,270,370 and vice-versa and may comprise one or more pressure relief valves 171,271,371 disposed in-line with one or more metering orifices 172,272,372, and at least one check valve 173,273,373 having at least one filter 174,274,374. An inner surface of pressure piston assembly 170,270,370 may comprise one or more inner sealing elements 175,275,375 and remain in slidable contact with drive mandrel 142 (in the first embodiment), second sleeve member 282 (in the second embodiment) or release mandrel 344 (in the third embodiment) while an outer surface of pressure piston assembly 170,270,370 may comprise one or more outer sealing elements 176,276,376 and may remain in slidable contact with drive housing 111,211 (in the first and second embodiments) or release housing 318 (in the third embodiment). Pressure piston assembly 170,270,370 divides the first annular fluid chamber of cable-head cutter tool 100,200,300 into a proximal portion extending from the distal portion of seal housing 103,203,303 to the proximal surface of pressure piston 170,270,370 and a distal portion extending from the distal surface of pressure piston 170,270,370 to the proximal surface of balancing piston 150,250,350. In operation, pressure piston assembly 170,270,370 acts to provide a time-delay as the drive mandrel of cable-head cutter tool 100,200,300 is moved in a proximal direction. In the closed, or run-in, configuration, pressure piston assembly 170,270,370 may be positioned in resting contact against drive housing shoulder 111 a,211a (in the first and second embodiments) or release housing shoulder 318 a (in the third embodiment).

Referring to FIGS. 1 a through 1 c and 2 a through 2 c , the embodiment-specific componentry of cable-head cutter tool 100 may comprise drive housing 111 surrounding drive mandrel 142, providing an annular cavity in which biasing element 160 and pressure piston assembly 170 may be located. Drive mandrel 142 may be formed having an overall length which allows cutter press 140 to be positioned away from a proximal surface of seal housing 103 while the distal surface of drive mandrel 142 is in resting contact with the proximal surface of filling sub 112. Biasing element 160 may be any suitable biasing element, for example a coiled spring. A proximal portion of biasing element 160 may be in contact with a distal surface of seal housing 103 (in the first embodiment), and a distal portion of biasing element 160 may be in contact with a proximal surface of pressure piston assembly 170. Biasing element 160 may be axially compressed between seal housing 103 and pressure piston 170, and configured to bias pressure piston 170 in the distal direction.

Referring to FIGS. 3 a through 3 c, 4 a through 4 c, and 5 a through 5 c , the embodiment-specific componentry of cable-head cutter tool 200 may comprise drive housing 211 surrounding drive mandrel 242, providing an annular cavity in which tripping valve mechanism 280, biasing element 260, and pressure piston assembly 270 may be located.

Drive mandrel 242 may be formed having an overall length which allows cutter press 240 to be positioned away from a proximal surface of seal housing 203 while the distal surface of drive mandrel 242 is in resting contact with the proximal surface of filling sub 212. Drive mandrel 242 may be provided with a plurality of longitudinal grooves about its outer surface which may extend from about a middle portion of drive mandrel 242 to a distal portion of drive mandrel 242 located proximally to the enlarged distal portion of drive mandrel 242. Each of the plurality of longitudinal grooves may provide a passage to allow flow of a hydraulic fluid from the middle portion of drive mandrel 242 to the distal portion of drive mandrel 242, and vice-versa, with such passages formed by first sleeve member 281 and second sleeve member 282 tightly overlying and enclosing drive mandrel 242, as will be described below.

Tripping valve mechanism 280 may be similar to that described by U.S. Pat. No. 4,566,546, the entire content of which is incorporated herein by reference thereto. Tripping valve mechanism 280 may comprise first sleeve member 281, second sleeve member 282, and tripping valve 283.

First sleeve member 281 and second sleeve member 282 may be generally tubular in form. First sleeve member 281 may be tightly fitted over a proximal portion of drive mandrel 242 extending from about the threaded proximal portion of drive mandrel 242 to about a middle portion of drive mandrel 242. Second sleeve member 282 may be tightly fitted over a distal portion of drive mandrel 242 extending from about the middle portion of drive mandrel 242 to a distal portion of drive mandrel 242 which may approach or abut the enlarged distal portion of drive mandrel 242. In embodiments, a proximal end of the longitudinal grooves formed on the outer surface of drive mandrel 242 may be located about the middle portion of drive mandrel 242 so as to be enclosed by a distal portion of first sleeve member 281, and second sleeve member 282 may abut first sleeve member 281 about this middle portion of drive mandrel 242. In this manner, sleeve members 281,282 enclosing the grooves of drive mandrel 242 may define a system of longitudinally extending fluid passages along drive mandrel 242.

First sleeve member 281 may be provided with a plurality of apertures 281 b located about its distal end which may allow fluid communication between an outer distal surface of first sleeve member 281 and the system of longitudinally extending fluid passages along drive mandrel 242. First sleeve member 281 may be formed having enlarged portion 281 a located about its distal end, and proximal to apertures 281 b, which may be adapted to provide a seat against which tripping valve 283 may be seated. In operation, tripping valve 283 being seated against enlarged portion 281 a may restrict the ability of fluid to flow through apertures 281 b and the longitudinal fluid passages formed between drive mandrel 242 and sleeve members 281,282.

Second sleeve member 282 may be provided with a plurality of apertures 282 b located about its distal end which may allow fluid communication between the system of longitudinally extending fluid passages along drive mandrel 242 and the annular cavity formed between drive housing 211 and drive mandrel 242 located distally to pressure piston assembly 270. Second sleeve member 282 may be formed having enlarged portion 282 a located about its distal end, and proximal to apertures 282 b, which may be adapted to provide a seat against which pressure piston assembly 270 may be seated. In operation, pressure piston assembly 270 being seated against enlarged portion 282 b may cause pressure piston assembly 270 to shift within cable-head cutter tool 200 in coordination with mandrel system 249 in the proximal direction, while allowing pressure piston assembly 270 to shift in the distal direction independently of mandrel system 249.

Tripping valve 283 may be formed as a generally tubular valve member having a cylindrical bore which may allow tripping valve 283 to remain in slidable contact with an outer surface of second sleeve member 282. One or more sealing elements 284 may be disposed in one or more recessed inner surfaces of the distal portion of tripping valve 283, which may form a slidable seal between the distal portion of tripping valve 283 and the outer surface of second sleeve member 282. Tripping valve 283 may be formed having an enlarged tubular extension about its proximal end with an internal profile adapted to receive and seat against first sleeve member enlarged portion 281 a, which may provide a metal-to-metal seal between tripping valve 283 and tripping valve seat 281 a. The enlarged tubular extension of tripping valve 283 may further be provided with one or more apertures 283 a allowing fluid communication between an outer and inner surface of the enlarged tubular extension. In embodiments, each of the one or more sealing elements 284 may be any suitable sealing element, for example an O-ring, and may be formed from any suitable material, for example nitrile (buna-N), ethylene propylene rubber (EPR), fluorocarbon (viton), neoprene, or polyurethane.

Biasing element 260 may be any suitable biasing element, for example a coiled spring. A proximal portion of biasing element 260 may be in contact with a distal surface of tripping valve 283, and a distal portion of biasing element 260 may be in contact with a proximal surface of pressure piston assembly 270. In this manner, biasing element 260 may be compressed between tripping valve 283 and pressure piston 270, thus biasing tripping valve 283 to be seated against first sleeve member valve seat 281 a and biasing pressure piston assembly 270 to be seated against second sleeve member enlarged portion 282 a.

Referring now to FIGS. 6 a through 6 c, 7 a through 7 c, and 8 a through 8 c , the embodiment-specific componentry of cable-head cutter tool 300 will be described.

Release housing 318 surrounds release mandrel 344, providing an annular cavity in which biasing element 360, pressure piston 370, and triggering mechanism 380 may be located. Release mandrel 344 may be formed having an overall length which allows the distal end of release mandrel 344 to be positioned about centrally within adjustment mandrel 319 when the distal surface of drive mandrel 342 is in resting contact with the recessed proximal surface of filling sub 312. Release mandrel 344 may be formed having an outer diameter about a central portion of its length which may allow release mandrel 344 to be in slidable contact with an inner surface of pressure piston 370. A proximal portion of biasing element 360 may be in contact with a distal surface of filling sub 312, while a distal portion of biasing element 360 may be in contact with a proximal surface of pressure piston 370. Drive mandrel 342 may be formed having an overall length which allows cutter press 340 to be positioned away from a proximal surface of seal housing 303 while the distal surface of drive mandrel 342 is in resting contact with the recessed proximal surface of filling sub 312.

Biasing element 390 may be disposed within an annular cavity formed between filling sub 312 and release mandrel 344 and surrounding a proximal portion of release mandrel 344. Biasing element 390 may be any suitable biasing element, for example a coil spring, and may be referred to as a “recocking spring”. A proximal portion of biasing element 390 may be in contact with an internal shoulder formed within a proximal portion of filling sub 312, while a distal portion of biasing element 390 may be in contact with a shoulder formed on the surface of a proximal portion of release mandrel 344. In this manner, biasing element 390 is configured to bias release mandrel 344 in the distal direction.

Biasing element 360 may be any suitable biasing element. For example, biasing element 360 may be a Belleville spring stack. One or more biasing element guides 361 may be disposed between biasing element 360 and release mandrel 344 and may be any suitable biasing element guide. For example, biasing element guide 361 may be a Belleville spring guide similar to that described in U.S. Pat. No. 7,854,425, the entire content of which is incorporated herein by reference thereto. Biasing element 360 may be axially compressed and configured to bias pressure piston 370 in the distal direction.

Triggering mechanism 380 may be similar to that described by U.S. Pat. No. 9,428,980, the entire content of which is incorporated herein by reference thereto. Triggering mechanism 380 may comprise compression ring 381, release mechanism, dog clutch, load release latch, or collet 382, one or more garter springs 383, guide ring 384, trigger sleeve 385, split ring retainer 386, and biasing element 387.

Compression ring 381 may surround release mandrel 344, with an inner surface of compression ring 381 remaining in slidable contact with an outer surface of release mandrel 344. A distal surface of compression ring 381 may contact a proximal surface of release mechanism 382, and a proximal surface of compression ring 381 may be available to contact a distal surface of pressure piston 370.

Release mechanism, dog clutch, load release latch, or collet 382 may be similar to that described by U.S. Pat. No. 10,669,800, the entire content of which is incorporated herein by reference thereto. Release mechanism, dog clutch, load release latch, or collet 382 may comprise a plurality of release lugs which may include a plurality of projections of varying width on an inner surface adapted to engage a corresponding plurality of recessed grooves on an outer surface of release mandrel 344, and a plurality of grooves on an outer surface which may be adapted to receive a corresponding plurality of projections on an inner surface of trigger sleeve 385. Each of the plurality of release lugs comprising release mechanism, dog clutch, load release latch, or collet 382 may be radially separated by an axial space and may be provided with a plurality of smaller grooves on an outer surface which may be adapted to hold garter springs 383. Garter springs 383 may circumferentially surround the plurality of release lugs, allowing for radial expansion and contraction of release mechanism, dog clutch, load release latch, or collet 382. A recessed inner profile of each of the plurality of release lugs comprising release mechanism, dog clutch, load release latch, or collet 382 may be adapted to surround guide ring 384, holding them in axial alignment while traveling along an outer surface of release mandrel 344.

Trigger sleeve 385 may be generally tubular, and may be radially positioned between release housing 318 and release mechanism, dog clutch, load release latch, or collet 382. Trigger sleeve 385 may be axially positioned between shoulder 318 b and a proximal surface of adjustment mandrel 319. Trigger sleeve 385 may slidably engage release housing 318, and thus may be generally free to move axially between shoulder 318 b and a proximal surface of adjustment mandrel 319, as allowed by biasing element 387. Trigger sleeve 385 may have a radially outer cylindrical surface that slidingly engages release housing 318, respectively, and a radially inner surface that includes a plurality of annular recesses defining a plurality of radially inwardly projecting annular flanges. Each of the plurality of flanges may be axially disposed between each of the plurality of adjacent recesses. As will be described in more detail below, each of the plurality of recesses and flanges may be sized and configured to releasably engage a plurality of mating flanges and recesses, respectively, provided on the radially outer surface of release mechanism, dog clutch, load release latch, or collet 382.

Split ring retainer 386 may be generally tubular, and may be formed having an outer diameter which may allow split ring retainer 386 to be in contact with an internal surface of release housing 318. Split ring retainer 386 may comprise a proximal lip which is adapted to be received by a recessed radial profile of trigger sleeve 385 and a distal lip which is adapted to be received by a recessed radial profile of adjustment mandrel 319.

Biasing element 387 may be any suitable biasing element, for example a coiled spring. A proximal portion of biasing element 387 may be in contact with, seated, or adapted to be received by a distal shoulder, seat, or recess of trigger sleeve 385, and a distal portion of biasing element 387 may be in contact with, seated, or adapted to be received by a proximal shoulder, seat, or recess of adjustment mandrel 319. Biasing element 387 may be axially compressed and configured to bias trigger sleeve 385 into engagement with shoulder 318 b.

The outer radial diameters of release mechanism, dog clutch, load release latch, or collet 382 and compression ring 381 may be sized to allow release mechanism, dog clutch, load release latch, or collet 382 and compression ring 381 to slidably pass shoulders 318 a and 318 b while allowing fluid communication between the proximal and distal portions, respectively thereto, of the first annular fluid chamber of cable-head cutter tool 300.

FUNCTIONAL ASPECTS AND OPERATION

Each embodiment of cable-head cutter tool 100,200,300 described herein may be provided with componentry which may exhibit similar functional aspects across each embodiment, yet different combinations of such componentry provided within each embodiment of cable-head cutter tool 100,200,300 may result in differing aggregate functional aspects, behaviors, features, and benefits specific to each embodiment. Examples of such componentry may include mandrel system 149,249,349, biasing element 160,260,360, and pressure piston assembly 170,270,370, while embodiment-specific componentry may include tripping valve mechanism 280 (in the second embodiment), and adjustment mandrel 319, triggering mechanism 380, and reset biasing element 390 (in the third embodiment). The individual functional aspects of such componentry may be the same or similar to those described by U.S. Pat. No. 10,202,815, U.S. Pat. No. 9,428,980, U.S. Pat. No. 8,443,902, U.S. Pat. No. 7,510,008, and U.S. Pat. No. 4,566,546, the entire contents of which are incorporated herein by reference thereto.

For simplicity of reference, mandrel system 149,249,349 of cable-head cutter tool 100,200,300 may comprise individual mandrel components 140,142,148, individual mandrel components 240,242,248, or individual mandrel components 340,342,344,346,348, respectively. In operation, an increase in a tensile load applied to wireline cable 401 may be transferred to mandrel system 149,249,349 via wireline cable termination 420, which may result in mandrel system 149,249,349 becoming biased toward a proximal direction. Similarly, a relaxation of a tensile load applied to wireline cable 401 may be transferred to mandrel system 149,249,349 via wireline cable termination 420, which may result in a reduction of bias of the mandrel system 149,249,349 toward a proximal direction. Slack wireline conductor 431 may provide sufficient slack within connection housing 132,232,332 to allow mandrel system 149,249,349 to travel a longitudinal distance in a proximal direction which may allow cutter press 140,240,340 to be fully seated against cutting mechanism seat 415 without applying tension to a portion of wireline cable 401 located distally relative to wireline cable termination 420.

As previously described, pressure piston assembly 170,270,370 divides the first annular fluid chamber of cable-head cutter tool 100,200,300 into a proximal portion and a distal portion. Each of the one or more pressure relief valves 171,271,371 of pressure piston assembly 170,270,370 may prevent fluid communication through pressure piston assembly 170,270,370 until a fluid pressure of the proximal portion of the first annular fluid chamber acting upon the proximal surface of pressure piston assembly 170,270,370 exceeds a cracking, or opening, pressure of pressure relief valve 171,271,371. Once pressure relief valve 171,271,371 is opened, fluid communication through pressure piston assembly 170,270,370 may be governed by metering orifice 172,272,372 disposed in-line with pressure relief valve 171,271,371. It should be noted that a temperature increase experienced by cable-head cutter tool 100,200,300 upon being lowered into a well may cause fluid pressure of the first annular fluid chamber to increase, which may cause balancing piston 150,250,350 to travel within balancing housing 126,226,326 in relation to a countering pressure of wellbore fluid entering through mud ports 127,227,327.

When traveling longitudinally in a proximal direction, the movement of mandrel system 149,249,349 may be registered against and resisted by biasing element 160,260,360. Once registered, mandrel system 149,249,349 may not begin to travel further until a tensile load applied to wireline cable 401 exceeds a preload force provided by biasing element 160,260,360. Axial compression of biasing member 160,260,360 resulting from continued travel of mandrel system 149,249,349 may generate an increasing spring force that may increasingly resist continued axial movement of mandrel system 149,249,349.

As longitudinal travel of mandrel system 149,249,349 is registered against a distal surface of pressure piston assembly 170,270,370, pressure piston assembly 170,270,370 may begin to travel together with mandrel system 149,249,349. A working fluid occupying the first annular fluid chamber may further resist movement of mandrel system 149,249,349 in a proximal direction as the volume of the proximal portion of the first annular fluid chamber is reduced, thus causing a significant increase in the working fluid pressure within the proximal portion of the first annular fluid chamber. The hydraulic resistance provided by pressure piston assembly 170,270,370 and the mechanical resistance provided by biasing element 160,260,360 may thus allow a large buildup of potential energy in the working string of cable-head cutter tool 100,200,300. Over time, metering orifice 172,272,372 may allow working fluid to flow through pressure piston assembly 170,270,370, thereby slowly relieving the pressure in the proximal portion of the first annular fluid chamber of cable-head cutter tool 100,200,300. It is this bleeding of working fluid across pressure piston assembly 170,270,370 which defines a hydraulic time-delay portion of a firing cycle of cable-head cutter tool 100,200,300. If a tensile load applied to wireline cable 401 is maintained at a level sufficient to overcome the preload force provided by biasing element 160,260,360 and the increasing spring force resulting from axial compression of biasing element 160,260,360, mandrel system 149,249,349 may continue to move longitudinally in a proximal direction.

Increasing the tensile load applied to wireline cable 401 may cause an increase in the potential energy built-up through the hydraulic resistance provided by pressure piston assembly 170,270,370 and the mechanical resistance provided by biasing element 160,260,360 as mandrel system 149,249,349 travels in a proximal direction. Holding steady the tensile load applied to wireline cable 401 may result in a decrease of this potential energy as pressure from the proximal portion of the first annular fluid chamber is relieved through pressure piston assembly 170,270,370 to the distal portion. Decreasing the tensile load applied to wireline cable 401 may cause a decrease in this potential energy based on relaxing the compressive force applied to biasing element 160,260,360, and may result in cable-head cutter tool 100,200,300 returning to its run-in configuration as a result of biasing element 160,260,360 biasing mandrel system 149,249,349 in a distal direction. During this resetting, or re-cocking, of cable-head cutter tool 100,200,300, check valve 173,273,373 may allow fluid which may have passed to the distal portion of the first annular fluid chamber to return rapidly to the proximal portion of the first annular fluid chamber through pressure piston assembly 170,270,370.

Prior to deploying cable-head cutter tool 100,200,300, an operator may determine one or more forces which may act upon or be imposed upon cable-head cutter tool 100,200,300 when deployed in a well. These may include, but not be limited to, the weight of the tool string including cable-head cutter tool 100,200,300 which will be supported by wireline cable 401, any buoyancy forces which may act upon the tool string and which may vary based upon a depth of the tool string relative to a column of fluid present in the well, a maximum tension which may be applied to wireline cable 401 to maintain a desired level of safety, a desired tensile load which may be applied to wireline cable 401 in order to activate wireline cable cutting mechanism 410, or a desired amount of time required to pass after applying the tensile load required to activate wireline cable cutting mechanism 410, or combinations thereof. The operator may determine these forces through a process of modeling, which may take into account one or more additional factors which may be present in or act upon the well, for example geological, environmental, temperature, pressure, or other such factors. The operator may then select an appropriate embodiment of cable-head cutter tool 100,200,300, and in the third embodiment may set cable-head cutter tool 300 to a desired configuration based upon the modeling by adjusting the tensile load required to be applied to wireline cable 401 in order to activate the wireline cable cutting mechanism 410, which may be done by adjusting the configuration of adjustment mandrel 319 in a manner which will be described below. Prior to deploying cable-head cutter tool 100,200,300, the operator may add a restraining element such as an O-ring, sticky tape, glue, or other adhesive forms to wireline cable 401 at a location proximal to where wireline cutting mechanism 410 may cut the wireline cable 401.

Once set to the operator’s desired configuration, the operator may deploy the tool string comprising cable-head cutter tool 100,200,300 into the well by lowering the tool string from the surface using wireline cable 401 to control its descent. In a complimentary manner, the operator may retrieve the tool string comprising cable-head cutter tool 100,200,300 from the well by applying or adjusting a lifting force to wireline cable 401 to control its ascent. During ascent, the tool string comprising wireline cable cutter tool 100,200,300 may become stuck in the well, which may result in an increased tensile load being applied to wireline cable 401, which in turn may cause mandrel system 149,249,349 to become biased in a proximal direction relative to the housing system of cable-head cutter tool 100,200,300 in the manner described. If the tool string becomes stuck in the well, the operator may proceed to increase, decrease, or hold steady the tensile load applied to wireline cable 401, or may proceed to adjust the tensile load applied to wireline cable 401 over a length of time through combinations of increasing, decreasing, or holding steady the tensile load applied to wireline cable 401. In this manner, mandrel system 149,249,349 may closely follow changes in tension applied to wireline cable 401, and may be caused to travel in relation to the housing system of cable-head cutter tool 100,200,300.

Cable-head cutter tool 100,200,300 may cut wireline cable 401 if the tensile load applied to wireline cable 401 is sufficient enough to cause mandrel system 149,249,349 to travel in a proximal direction and allow cutter press 140,240,340 to engage wireline cable cutting mechanism 410. Upon causing wireline cable cutting mechanism 410 to cut wireline cable 401, the operator may retrieve the now cut wireline cable 401 from the well and proceed to recover the tool string comprising cable-head cutter tool 100,200,300 from the well using an appropriate means which may rely upon engagement of fishing neck 101,201,301. Each embodiment of cable-head cutter tool 100,200,300 may vary in the method though which wireline cable 401 may be cut, which will now be described.

Referring again to FIGS. 1 a through 1 c and 2 a through 2 c , travel of mandrel system 149 in a proximal direction may be initially prevented by a proximal surface of the enlarged distal portion of drive mandrel 142 acting against a distal surface of pressure piston assembly 170, until the fluid pressure of the proximal portion of the first annular fluid chamber, acting upon the proximal surface of pressure piston assembly 170, exceeds the cracking, or opening, pressure of pressure relief valve 171. Upon opening pressure relief valve 171, the rate of travel of mandrel system 149 in the proximal direction will be governed by a mechanical resistance provided by biasing element 160 and a rate of fluid communication allowed through metering orifice 172. As mandrel system 149 travels in a proximal direction, pressure piston assembly 170 may cause biasing element 160 to become increasingly compressed, and thus increasingly resist continued travel of mandrel system 149, as working fluid passes through pressure piston assembly 170 from the proximal portion to the distal portion of the first annular fluid chamber. If the tensile load applied to wireline cable 401 is sufficient to overcome the increasing resistance provided by biasing element 160, continued forward travel of mandrel system 149 may cause a proximal surface of cutter press 140 to engage a distal surface of wireline cable cutting mechanism 410, thereby actuating wireline cable cutting mechanism 410 and thus cutting wireline cable 401. At any time prior to cutter press 140 engaging wireline cable cutting mechanism 410, relaxation of the tensile load applied to wireline cable 401 may cause this progressive sequence to be reversed. In operation, cable-head cutter tool 100 may provide an operator with an ability to gradually progress toward cutting wireline cable 401 through an increase in tensile load applied to wireline cable 401.

Referring again to FIGS. 3 a through 3 c, 4 a through 4 c, and 5 a through 5 c , the operational aspects of cable-head cutter tool 200 will now be described.

As cable-head cutter tool 200 begins to undertake a progressive sequence toward causing wireline cable cutting mechanism 410 to cut wireline cable 401, initial travel of mandrel system 249 in a proximal direction may cause a proximal surface of the enlarged distal portion of second sleeve member 282 a to engage a distal surface of pressure piston assembly 270. Continued travel of mandrel system 249 in a proximal direction may then be restricted until a fluid pressure of the proximal portion of the first annular fluid chamber acting upon the proximal surface of pressure piston assembly 270 exceeds an opening pressure of pressure relief valve 271, as previously described. Once permitted by pressure relief valve 271 to travel further in the proximal direction, mandrel system 249 may continue to travel in coordination with pressure piston assembly 270, biasing element 260, and tripping valve 283, as a result of second sleeve member portion 282 a acting upon pressure piston assembly 270. During this continuing travel, fluid pressure in the proximal portion of the first annular fluid chamber may increase substantially, with the rate of travel of mandrel system 249 governed by a rate at which hydraulic fluid may be allowed to communicate through metering orifice 272. Throughout this initial sequence of travel of mandrel system 249, the inner profile of tripping valve 283 may remain seated against first sleeve member enlarged portion 281 a.

At an intermediate point of travel, a proximal surface of the enlarged tubular extension of tripping valve 283 may register against a distal surface of seal housing 203, preventing tripping valve 283 from continuing to travel in coordination with mandrel system 249, and causing biasing element 260 to become increasingly compressed as pressure piston assembly 270 may continue to travel in coordination with mandrel system 249. If the tensile load applied to wireline cable 401 is sufficient to create a pressure in the proximal portion of the first annular fluid chamber that exceeds the cracking pressure of pressure relief valve 271, continuing travel of mandrel system 249 in the proximal direction may cause the internal profile of tripping valve 283 to become unseated from the distal surface of first sleeve member enlarged portion 281 a, thus opening, or tripping, the valve. Upon becoming tripped in this manner, fluid located in the annular fluid chamber proximal to tripping valve 283, now under very high pressure and resisting further travel of mandrel system 249, may become freed to pass through apertures 283 a of tripping valve 283 and apertures 281 b of first sleeve member 281, thus becoming free to travel from the proximal portion to the distal portion of the first annular fluid chamber via the fluid passages formed between drive mandrel 242 and sleeve members 281,282. Mandrel system 249, now being freed of the hydraulic resistance, may continue to travel in the proximal direction, with first sleeve member enlarged distal portion 281 a passing through the expanded internal bore of seal housing 203 until cutter press 240 engages a distal surface of wireline cable cutting mechanism 410, thereby actuating wireline cable cutting mechanism 410 and thus cutting wireline cable 401

At any point prior to the tripping of valve 283, relaxation of the tensile load applied to wireline cable 401 may allow the progressive sequence to be reversed from the point at which the tensile load is reduced. Fluid which may have flowed from the proximal side of pressure piston assembly 270 to the distal side through pressure relief valve 271 may be forced back through check valve 273 due to biasing member 260.

In operation, cable-head cutter tool 200 may provide an operator with an ability to cut wireline cable 401 through an increase in tensile load applied to wireline cable 401 which may cause wireline cable 401 to become stretched and cause a rapid release of inertia built-up within cable-head cutter tool 200, thereby cutting wireline cable 401 by means of sudden impact once mandrel system 249 becomes freed.

Referring again to FIGS. 6 a through 6 c, 7 a through 7 c, and 8 a through 8 c , cable-head cutter tool 300 may provide an operator with an ability to adjust the tensile load required to be applied to wireline cable 401 before triggering mechanism 380 may release mandrel system 349.

Adjustment mandrel 319 may be threadably received at a proximal portion by release housing 318, and may be threadably received at a distal portion by adjustment housing 323. The proximal and distal threads of adjustment mandrel 319 may be oppositely threaded, such that rotation of adjustment mandrel 319 about its longitudinal axis may result in axial translation of adjustment mandrel 319 relative to release housing 318. This axial translation may thus vary the position of trigger sleeve 385 in relation to release mechanism, dog clutch, load release latch, or collet 382, which may thereby adjust the amount of axial travel of mandrel system 349 required before allowing triggering mechanism 380 to become triggered. Reset biasing element 390 may bias mandrel system 349 to travel in a distal direction. In this manner, relaxing a tensile load applied to wireline cable 401 may allow reset biasing element 390 to bias cable-head cutter tool 300 to return to its initial configuration prior to triggering mechanism 380 becoming triggered.

Triggering mechanism 380 may serve to regulate communication between mandrel system 349 and biasing element 360. In an initial, closed, or run-in, configuration, an internal profile of release mechanism, dog clutch, load release latch, or collet 382 may engage a complimentary external profile of release mandrel 344, which may result from garter springs 383 causing release mechanism, dog clutch, load release latch, or collet 382 to close around the complimentary external profile of release mandrel 344. As mandrel system 349 travels in a proximal direction, an external profile of release mechanism, dog clutch, load release latch, or collet 382 may come into alignment with a complimentary internal profile of trigger sleeve 385, which may allow release mechanism, dog clutch, load release latch, or collet 382 to expand radially to a second, or open, configuration. In this manner, release mechanism, dog clutch, load release latch, or collet 382 becoming fully registered against trigger sleeve 385 may provide sufficient clearance between the complimentary surfaces of the internal profile of release mechanism, dog clutch, load release latch, or collet 382 and the external profile of release mandrel 344 so as to allow mandrel system 349 to travel without engaging release mechanism, dog clutch, load release latch, or collet 382, and thus not communicate its travel to biasing element 360.

Reversing the steps just described, when release mechanism, dog clutch, load release latch, or collet 382 may be fully registered against trigger sleeve 385, mandrel system 349 may travel in a distal direction free from engagement with release mechanism, dog clutch, load release latch, or collet 382. As the external profile of release mandrel 344 comes into alignment with the complimentary internal profile of release mechanism, dog clutch, load release latch, or collet 382, release mechanism, dog clutch, load release latch, or collet 382 may return to the initial, closed, or run-in, configuration fully engaging release mandrel 344, which may result from garter springs 383 causing release mechanism, dog clutch, load release latch, or collet 382 to close around the complimentary external profile of release mandrel 344. In this manner, release mechanism, dog clutch, load release latch, or collet 382, becoming fully registered against release mandrel 344, may provide sufficient clearance between the complimentary surfaces of the external profile of release mechanism, dog clutch, load release latch, or collet 382 and the internal profile of trigger sleeve 385 so as to allow mandrel system 349 to travel in engagement with release mechanism, dog clutch, load release latch, or collet 382 in a distal direction without engaging trigger sleeve 385.

As cable-head cutter tool 300 begins to undertake a progressive sequence toward causing wireline cable cutting mechanism 410 to cut wireline cable 401, initial travel of mandrel system 349 in a proximal direction (upon overcoming the hydraulic resistance of pressure relief valve 369) may cause biasing element 360 to immediately begin to compress due to a proximal surface of release mechanism, dog clutch, load release latch, or collet 382 acting against compression ring 381, which in turn acts against pressure piston assembly 363, which in turn acts against biasing element 360. Continued travel of mandrel system 349 in a proximal direction may next cause biasing element 360 to become increasingly compressed, and thus increasingly resist continued travel of mandrel system 349 as working fluid passes through pressure piston assembly 363 from the proximal portion to the distal portion of the first annular fluid chamber. If the tensile load applied to wireline cable 401 is sufficient to overcome the increasing resistance of biasing element 360, release mechanism, dog clutch, load release latch, or collet 382 may come into alignment with and expand to register against trigger sleeve 385 and thus free mandrel system 349 to travel unrestrained in a proximal direction until a proximal surface of cutter press 340 engages a distal surface of wireline cable cutting mechanism 410, thereby actuating wireline cable cutting mechanism 410 and thus cutting wireline cable 401. Relaxation of the tensile load applied to wireline cable 401 prior to actuation of wireline cable cutting mechanism 410 may cause this progressive sequence to be reversed from the point at which the tensile load is reduced, wherein a continued relaxation of the tensile load may result in cable-head cutter tool 300 returning to its run-in configuration as a result of biasing element 390 biasing mandrel system 349 in a distal direction. In operation, cable-head cutter tool 300 may provide an operator with an ability to cut wireline cable 401 through an increase in tensile load applied to wireline cable 401 which may cause wireline cable 401 to become stretched and cause a rapid release of inertia built-up within cable-head cutter tool 300, thereby cutting wireline cable 401 by means of sudden impact once mandrel system 349 becomes freed. In operation, mandrel system 349 of cable-head cutter tool 300 may not become free to travel until the pressure in the proximal fluid chamber exceeds a cracking pressure of pressure relief valve 369. In this manner, the tensile load required to cause mandrel system 349 to begin to travel may be the sum of the load required to overcome biasing element 360 and the additional tensile load required to overcome the cracking pressure of pressure relief valve 369.

The time-controlled cable-head cutter for line conveyed tools, embodiments, and methods just described may provide a number of features and benefits not presently available in the art. Such features and benefits may include a cable cutter disposed internally within a housing, which may allow the cable, once cut, to be retrieved free of tool string equipment, with the stuck tool string providing an unobstructed fishing neck available for subsequent retrieval. Additionally, the time-controlled cable-head cutter may be configured to be activated based upon a predetermined or desired tensile load being applied to a wireline cable, a predetermined or desired time delay following application of a tensile load to a wireline cable, or combinations thereof. In this manner, and in combination with the ability to reset the time-controlled cable-head cutter, an operator may be able to perform an unlimited number of safe, high-tension pulls or may be able to perform numerous wireline runs without the need to re-head the wireline cable. Further, the time-controlled cable-head cutter may be insensitive to firing shocks from wireline conveyed perforating guns.

By providing an operator with the ability to adjust the release tension through the adjustment mandrel in the third embodiment, the time-controlled cable-head cutter may offer operational benefits over prevailing alternatives whereby it may be necessary for an operator to have ready different sets of cable-heads having different release tensions. Additional operational benefits may be available in each of the embodiments of the time-controlled cable-head cutter, whereby an operator may be able to re-head a wireline cable without the need to disassemble the time-controlled cable-head cutter.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made herein without departing from the spirit and scope of the invention as defined by the appended claims. 

What is claimed is:
 1. A system comprising: a cable head cutter tool comprising an outer housing, an outer housing connector, an internal mandrel, and a combination of mechanical and hydraulic devices disposed within the outer housing which act upon the mandrel; a tool string connected to the outer housing connector; a line connected to the internal mandrel; wherein at least one of the hydraulic devices comprises at least one pressure relief valve; wherein the internal mandrel is held biased into a first position within the outer housing by a resistance provided by the combination of mechanical and hydraulic devices; wherein the internal mandrel is released from the first position by applying tension on the line which exceeds a release tension and then maintaining an applied tension for a duration which exceeds a release duration, until the internal mandrel is by the combination of mechanical and hydraulic devices thereby allowing the internal mandrel to travel unrestricted within the outer housing; and wherein upon being -freed the internal mandrel travels toward a second position at which the internal mandrel contacts a line cutting mechanism disposed within the outer housing, causing the line cutting mechanism to cut the line.
 2. The system of claim 1, wherein the line is a slickline, a braided line, an electromechanical line, a flexible rod, or a coiled tubing.
 3. The system of claim 1, wherein the line has a working tension limit and wherein the outer housing connector has a tensile strength limit greater than the working tension limit of the line.
 4. The system of claim 1, wherein the line cutting mechanism comprises a mechanical blade-based cutter, a ballistic cutter, or a chemical cutter.
 5. The system of claim 1, wherein the line cutting mechanism is coupled to the internal mandrel, wherein upon being released the internal mandrel travels toward a second position at which the line cutting mechanism contacts an inner profile of the outer housing, causing the line cutting mechanism to cut the line.
 6. The system of claim 1, wherein while applying the applied tension on the line and before the line cutting mechanism cuts the line, the mandrel is caused to be biased to the first position by reducing the applied tension.
 7. A method of releasing a line from a tool string, comprising: connecting a line to a cable head cutter tool with an anchoring method; supporting a tool string in a well with the line; applying tension to the line; holding the applied tension for a duration; releasing a mandrel of the cable head cutter tool from a first position when an applied tension exceeds a preset release tension and the duration of the applied tension exceeds a selected release duration, wherein the preset release tension and selected release duration are based upon a resistance provided by a combination of mechanical and hydraulic devices disposed within the cable head cutter tool, wherein at least one of the hydraulic devices comprises a pressure relief valve; freeing the mandrel from being coupled to a housing of the cable head cutter tool after the releasing, thereby freeing the mandrel to travel unrestricted within the housing which results in a line cutting mechanism cutting the line; and optionally reducing the applied tension below the preset release tension before the selected release duration is exceeded, thereby allowing the mandrel to be biased toward the first position.
 8. The method of claim 7, wherein external clamp-on subs or tools are mounted on a deployment line section above a fishing neck of the cable head cutter tool.
 9. A cable head cutter tool for raising and lowering a tool string within a well with a line, comprising: an outer housing comprising a connector adapted for connection to the tool string and an internal mandrel adapted for connection to the line; one or more locking mechanisms in communication with the outer housing and the internal mandrel, each locking mechanism comprising a locked configuration, a released configuration, and a freed configuration, wherein in the freed configuration the internal mandrel is freed to travel unrestricted within the outer housing independent of the locking mechanism, and wherein in the locked configuration and the released configuration, each of the one or more locking mechanisms communicates with the outer housing through a system of mechanical devices, a system of hydraulic devices comprising at least one pressure relief valve, or a system of mechanical devices and hydraulic devices comprising at least one pressure relief valve, thereby providing each of the one or more locking mechanisms with a release tension and a release duration; a line cutting mechanism disposed within the outer housing which cuts the line upon the internal mandrel communicating with the line cutting mechanism after the internal mandrel is freed by all of the one or more locking mechanisms; wherein each of the one or more locking mechanisms is caused to be shifted from the locked configuration to the released configuration based upon a tension applied to the line causing activation of the pressure relief valve and exceeding a preset release tension of the locking mechanism, and being held for a duration exceeding a selected release duration of the locking mechanism.
 10. The apparatus of claim 9, wherein the line cutting mechanism is coupled to the internal mandrel, wherein upon being released the mandrel travels toward a second position causing the line cutting mechanism to cut the line.
 11. The apparatus of claim 9, wherein a cutter of the line cutting mechanism is driven by a compression force applied to the line cutting mechanism after the mandrel is released.
 12. The apparatus of claim 9, wherein a cutter of the line cutting mechanism comprises a ballistic cutter or a chemical cutter.
 13. The apparatus of claim 9, wherein one or more hollow tools are disposed between a fishing neck and a proximal end of the outer housing. 